JP2023158441A - Tank manufacturing method - Google Patents

Abstract

To provide a technology for suppressing deterioration in an appearance quality of a finished tank product.SOLUTION: A tank manufacturing method includes: a placement step of placing a tank member including a hollow member and a fiber layer formed on an outer surface of the hollow member in a mold; a first injection step of injecting a first resin impregnated into the fiber layer and containing a curing agent between an inner surface of the mold and an outer surface of the tank member, after the placement step; a separating step in which an upper mold of the mold is separated from a lower mold of the mold by a predetermined distance, at a timing when a pressure between the inner surface of the mold and the outer surface of the tank member reaches a peak value, and the pressure has decreased from the peak value, after the first injection step; a second injection step of injecting a second resin containing paint between the inner surface of the mold and the outer surface of the tank member, after the separating step; and a pressing step of pressing the upper mold against the lower mold, after the second injection step.SELECTED DRAWING: Figure 2

Description

This specification discloses a tank manufacturing method for manufacturing a tank.

Patent Document 1 discloses a tank manufacturing method. The tank manufacturing method includes a step of installing a preform including a liner and a fiber layer in a mold, a step of supplying a first resin composition to the fiber layer, and a step of supplying a first resin composition to the fiber layer. a step of separating the mold from a lower mold by a predetermined distance and changing the mold to an unloaded state; a step of supplying a second resin composition to the fiber layer after changing the mold to an unloaded state; After supplying the resin composition No. 2, the method includes the step of bringing the upper mold closer to the lower mold and changing the mold to a tightened state.

Japanese Patent Application Publication No. 2021-151750

This specification provides a technique for suppressing deterioration in the appearance quality of a finished tank product.

The tank manufacturing method disclosed in this specification includes an arrangement step of arranging a tank member including a hollow member and a fiber layer formed on the outer surface of the hollow member in a mold, and after the arrangement step, the a first injection step of injecting a first resin to be impregnated into the fiber layer between an inner surface of a mold and an outer surface of the tank member, the first resin containing a curing agent; 1 injection step and after the first injection step, the pressure between the inner surface of the mold and the outer surface of the tank member reaches a peak value, and at a timing when the pressure decreases from the peak value, a separating step of separating the upper mold of the mold from the lower mold of the mold by a predetermined distance, and after the separating step, a second resin containing a paint between the inner surface of the mold and the outer surface of the tank member. and a pressing step of pressing the upper mold against the lower mold after the second injection step.

If the second resin is mixed with the first resin before the first resin starts curing, color unevenness, voids, etc. may occur on the surface of the second resin. Uneven coloring, voids, etc. cause deterioration in the appearance quality of the finished tank product. The inventor discovered that the timing at which the pressure between the inner surface of the mold and the outer surface of the tank member reached a peak and the pressure decreased from the peak value was the timing at which curing of the first resin started. . According to the above configuration, at the timing when the first resin starts to harden, the separating step is executed and the second resin is injected between the inner surface of the mold and the outer surface of the tank member. Mixing of the second resin with the uncured first resin is suppressed, and deterioration in the appearance quality of the finished product of the tank can be suppressed.

The second resin may include a reinforcing material that increases the adhesion of the second resin to the first resin.

According to the above configuration, the adhesion of the second resin to the first resin is improved, and it is possible to further suppress deterioration in the appearance quality of the finished product of the tank.

Details and further improvements of the technology disclosed in this specification will be explained in the following "Detailed Description of the Invention".

The configuration of the tank manufacturing equipment is shown. It is a flowchart figure of a tank manufacturing method. The steps of degassing and primary injection are shown. The process of lift-up and secondary injection is shown. The state of curing of the second resin is shown.

(Configuration of tank manufacturing equipment 2; Figure 1)
The tank manufacturing device 2 is a device that impregnates a tank member 10 with resin to manufacture a high-pressure tank for a fuel cell vehicle. The tank member 10 is an intermediate product of a high-pressure tank. The tank member 10 includes a hollow member 12 and a fiber layer 14. The fibrous layer 14 is formed by wrapping fibers around the outer surface of the hollow member 12. The fiber is, for example, carbon fiber.

The tank manufacturing apparatus 2 includes a mold 26, a curing agent tank 30, a pump 32, a first base agent tank 40, a second base agent tank 42, a switching valve 44, a pump 46, and a mixer 50. , is provided. The mold 26 includes an upper mold 20 and a lower mold 24. By overlapping the upper mold 20 and the lower mold 24, a space along the outer shape of the tank member 10 is formed. A pressure sensor 22 for measuring the pressure inside the mold 26 is provided on the inner surface of the upper mold 20. Note that the pressure sensor 22 may be provided on the inner surface of the lower mold 24, or a plurality of pressure sensors 22 may be provided on at least one of the inner surface of the upper mold 20 and the inner surface of the lower mold 24. good.

The curing agent tank 30 stores a curing agent. Pump 32 pumps the curing agent in curing agent tank 30 to mixer 50 . Pump 32 is installed on the flow path between curing agent tank 30 and mixer 50.

The first base agent tank 40 stores the first base agent to be injected into the mold 26 in a first injection step (see S4 in FIG. 3), which will be described later. The first base material is, for example, an epoxy resin. The first base agent mixes with the curing agent and is cured by a chemical reaction between the two.

The second base agent tank 42 stores a second base agent to be injected into the mold in a second injection step (see S8 in FIG. 3), which will be described later. The second base material is, for example, an epoxy resin. The second main ingredient includes a paint and a reinforcing material described below. The second base agent mixes with the curing agent and is cured by a chemical reaction between the two.

A flow path extending from the first base agent tank 40 is connected to a switching valve 44 . Further, a flow path extending from the second base agent tank 42 is also connected to the switching valve 44 . The switching valve 44 has two states: a first state in which the flow path extending from the first base agent tank 40 communicates with the pump 46, and a second state in which the flow path extending from the second base agent tank 42 communicates with the pump 46. set to one of them.

The pump 46 pumps the first base agent in the first base agent tank 40 or the second base agent in the second base agent tank 42 to the mixer 50 . Pump 46 is installed on the path between switching valve 44 and mixer 50.

The mixer 50 mixes the curing agent in the curing agent tank 30 with the first base agent in the first base agent tank 40 or the second base agent in the second base agent tank 42 . The mixer 50 pumps the mixed material (for example, a mixture of the first base material and the curing agent) to the mold 26 .

(Tank manufacturing method; Figures 2 to 4)
A tank manufacturing method for manufacturing a high-pressure tank by controlling the tank manufacturing apparatus 2 will be described with reference to FIG. 2.

FIG. 3 shows step S2 and step S4. In step S2, the tank member 10 is placed in the mold 26, and mold clamping is performed to press the upper mold 20 against the lower mold 24. Thereafter, degassing is performed to bring the space within the mold 26 (that is, the space between the inner surface of the mold 26 and the outer surface of the tank member 10) close to vacuum. Note that in each drawing, illustration of a device that performs deaeration is omitted.

In the following step S4, primary injection is performed. In the primary injection, the state of the switching valve 44 is set to the first state, and the hardening agent in the hardening agent tank 30 and the first base agent in the first base agent tank 40 are pumped to the mixer 50. . Then, the mixed material, ie, the mixture of the first base material and the curing agent (hereinafter referred to as "first mixture"), is pumped into the mold 26. The first mixture flows between the inner surface of the mold 26 and the outer surface of the tank member 10. While the first mixture is curing, the first mixture impregnates the fibrous layer 14 of the tank member 10. The primary injection is stopped once a predetermined amount of the first mixture has been injected.

On the right side of FIG. 2, a graph G1 showing the transition of the pressure inside the hollow member 12 and a graph G2 showing the transition of the pressure inside the mold 26 are shown. Regarding graphs G1 and G2, the horizontal axis indicates time and the vertical axis indicates pressure.

Timing t1 indicates the timing at which the primary injection started. As shown by graphs G1 and G2, the pressure within the hollow member 12 and the pressure within the mold 26 increase with the start of the primary injection. During the primary injection, the differential pressure between the pressure within the hollow member 12 and the pressure within the mold 26 is controlled.

Timing t2 indicates the timing at which the primary injection is stopped. As graph G2 shows, when the primary injection is stopped, the pressure inside the mold 26 decreases once, but then increases again. Thereafter, the pressure within the mold 26 reaches a peak value and decreases from the peak value at timing t3. Timing t3 at which the pressure within the mold 26 decreases from its peak value is detected using the transition of the measured value of the pressure sensor 22.

FIG. 4 shows steps S6 and S8. Step S6 is executed using the detection of timing t3 at which the pressure within the mold 26 has decreased from its peak value as a trigger. In step S6, the upper mold 20 is lifted up from the lower mold 24. Specifically, the upper mold 20 is separated from the lower mold 24 by a predetermined distance. Thereby, a predetermined gap is formed between the inner surface of the mold 26 and the outer surface of the tank member 10.

In the following step S8, secondary injection is performed. In the secondary injection, the state of the switching valve 44 is set to the second state, and the hardening agent in the hardening agent tank 30 and the second base agent in the second base agent tank 42 are pumped to the mixer 50. Ru. Then, the mixed material, ie, the mixture of the second base material and the curing agent (hereinafter referred to as "second mixture"), is pumped into the mold 26. The second mixture flows between the inner surface of the mold 26 and the outer surface of the tank member 10. The second mixture is applied around the first mixture.

In the following step S10, mold clamping in which the upper mold 20 is pressed against the lower mold 24 is performed again. Then, in step S12, when a predetermined amount of the second mixture is injected, the secondary injection is stopped.

Although not shown, the tank member 10 is taken out from the mold 26 after the second mixture is cured. The fiber layer 14 of the tank member 10 taken out is impregnated with the hardened first mixture, and the hardened second mixture is coated around the hardened first mixture. A high pressure tank is completed by the tank manufacturing method shown in FIG.

The inventor discovered that timing t3 in graph G2 of FIG. 2 (that is, the timing at which the pressure within the mold 26 decreased from the peak value) was the timing at which curing of the first mixture started. For example, a comparative example is assumed in which steps S6 and S8 are executed at a timing before timing t3. In this comparative example, the second mixture is injected into the mold 26 before the first mixture begins to harden. In this case, the second mixture may be mixed with the first resin before curing. When the second mixture and the first mixture are mixed, the second mixture may be cured with uneven color, voids, etc. occurring on the surface of the second mixture. Uneven coloring, voids, etc. cause deterioration in the appearance quality of the finished high-pressure tank.

According to the configuration of this embodiment, lift-up and secondary injection are performed at timing t3 when curing of the first mixture starts (S6 and S8). Mixing of the second mixture with the first mixture before curing is suppressed, and deterioration of the appearance quality of the high-pressure tank can be suppressed.

(Effect of reinforcing material; Figure 5)
The second base material includes a reinforcing material for increasing the adhesion of the second mixture to the first mixture. The reinforcing material is, for example, a glass microballoon. As shown in FIG. 5, in the secondary injection in step S8, the second mixture 110 is applied to the outer surface of the first mixture 100 that has started to harden. Here, voids 102 are generated on the outer surface of the first mixture 100 that has started to harden. As application of the second mixture 110 progresses, the reinforcing material 112 within the second mixture 110 penetrates into the voids 102. With the reinforcing material 112 penetrating into the void 102, the second mixture 110 is cured. The reinforcing material 112 exerts an anchoring effect on the void 102, increasing the adhesion of the second mixture to the first mixture. Thereby, deterioration in the appearance quality of the high-pressure tank can be further suppressed.

Further, the surface of the reinforcing material 112 is coated with a conductive material such as carbon or silver. This eliminates the need to separately apply a primer. Note that in a modified example, the surface of the reinforcing material 112 does not need to be coated with a conductive material.

(correspondence)
The hollow member 12, the fiber layer 14, and the tank member 10 are examples of a "hollow member," a "fiber layer," and a "tank member," respectively. The mold 26 is an example of a "mold". The first mixture 100, the second mixture 110, and the reinforcing material 112 are examples of the "first resin", "second resin", and "reinforcing material", respectively. The tank manufacturing method shown in FIG. 2 is an example of a "tank manufacturing method." S2, S4, S6, S8, and S10 are examples of a "placement step,""first injection step,""separationstep,""second injection step," and "pressing step," respectively. Timing t3 in FIG. 2 is an example of "timing".

Hereinafter, points to note regarding the technology shown in the examples will be described. Second mixture 110 may be free of reinforcing material 112.

Although specific examples of the present invention have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The techniques described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims as filed. Furthermore, the techniques illustrated in this specification or the drawings can achieve multiple objectives simultaneously, and achieving one of the objectives has technical utility in itself.

2: Tank manufacturing device 10: Tank member 12: Hollow member 14: Fiber layer 20: Upper mold 22: Pressure sensor 24: Lower mold 26: Mold 30: Curing agent tank 32: Pump 40: First base agent tank 42: Second base agent tank 44: Switching valve 46: Pump 50: Mixer 100: First mixture 102: Void 110: Second mixture 112: Reinforcement materials G1, G2: Graphs t1, t2, t3: Timing

Claims (2)

a step of arranging a tank member including a hollow member and a fiber layer formed on an outer surface of the hollow member in a mold;
After the placement step, a first injection step of injecting a first resin to be impregnated into the fiber layer between the inner surface of the mold and the outer surface of the tank member, the first resin comprising: the first injection step comprising a curing agent;
After the first injection step, when the pressure between the inner surface of the mold and the outer surface of the tank member reaches a peak value and the pressure decreases from the peak value, the upper mold of the mold is a separating step of separating the from the lower die of the mold by a predetermined distance;
After the separation step, a second injection step of injecting a second resin containing paint between the inner surface of the mold and the outer surface of the tank member;
a pressing step of pressing the upper mold against the lower mold after the second injection step;
A tank manufacturing method comprising: The tank manufacturing method according to claim 1, wherein the second resin includes a reinforcing material that increases adhesion of the second resin to the first resin.

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